Floating valve design (not fixed by a trunnion) is a good way to achieve a good sealing performance at lower costs. The ball drifts toward to the downstream side and tightly pushes against the seat under the medium pressure to ensure sealing reliability.
Floating ball valves have a simply structure, a good sealing performance but the seat material is required can support the workload. Due to unavailability of high performance seat material, floating ball valves is mainly used in middle or low pressure application.